Conveyor dishwasher and operating method for same

Abstract

A conveyor dishwasher includes a storage tank for holding sprayed final rinse liquid and a controllable liquid transfer device for transferring liquid from the storage tank to at least one wash zone as a function of a liquid demand in at least one of the wash zones.

1. A conveyor dishwasher for cleaning wares, comprising:
 a conveyor device for conveying wares in a direction of conveyance through at least two zones of the conveyor dishwasher, including at least one wash zone and at least one final rinse zone, the wash zone having spray nozzles, a tank and a pumping device for recirculating wash liquid from the tank to the spray nozzles and spraying wash liquid through the spray nozzles onto wares, the final rinse zone including spray nozzles for spraying final rinse liquid onto wares; 
 a storage tank for gathering sprayed final rinse liquid; 
 a liquid transfer device connected for controlling whether liquid is transferred from the storage tank to the wash zone; 
 at least one sensor device for determining liquid demand in the wash zone; and 
 a control unit configured for automatic operation of the liquid transfer device depending on liquid demand in the wash zone as indicated by the sensor device; 
 wherein the storage tank has an overflow over which liquid flows from the storage tank when liquid level in the storage tank exceeds a certain outflow level and the overflow is a path separate from a path defined by the liquid transfer device. 
 
     
     
       2. The conveyor dishwasher according to  claim 1  wherein the liquid transfer device includes a pump and a liquid line running from the storage tank to the wash zone and having an outlet to deliver liquid into the tank of the wash zone. 
     
     
       3. The conveyor dishwasher according to  claim 1 , wherein the at least one sensor device includes a turbidity sensor for detecting a degree of soiling of liquid in the tank of the wash zone, wherein the control unit operates the liquid transfer device when the detected degree of soiling in the tank of the wash zone is equal to or greater than a predetermined degree of soiling. 
     
     
       4. The conveyor dishwasher according to  claim 3 , wherein the at least one sensor device includes a liquid level sensor for detecting a level of the liquid in the tank of the wash zone, wherein the control unit operates the liquid transfer device when the detected liquid level in the tank of the wash zone is at or below a predetermined lower level. 
     
     
       5. The conveyor dishwasher according to  claim 1 , wherein the control unit operates the liquid transfer device for supplying liquid from the storage tank to the wash zone during initial filling of the conveyor dishwasher for initial filling of the tank. 
     
     
       6. The conveyor dishwasher according to  claim 1  wherein the wash zone is a rear wash zone, the dishwasher further including a front wash zone having a tank from which liquid is delivered to spray nozzles of the front wash zone, wherein the volume of the storage tank is no less than the sum of the volume of the tank of the front wash zone and the volume of the tank of the rear wash zone. 
     
     
       7. The conveyor dishwasher according to  claim 1  further comprising a fresh water supply device that supplies fresh water to the storage tank, and at least one sensor device provided for determining fresh water demand in the storage tank, wherein the control unit controls the fresh water supply device as a function of fresh water demand in the storage tank to supply fresh water to the storage tank when there is a demand for fresh water. 
     
     
       8. The conveyor dishwasher according to  claim 7 , wherein the at least one sensor device comprises a liquid level sensor for detecting a level of liquid in the storage tank, wherein the control unit operates the fresh water supply device and thereby supplies fresh water to the storage tank when the detected liquid level in the storage tank is equal to a predetermined lower level. 
     
     
       9. The conveyor dishwasher according to  claim 7 , wherein the at least one sensor device comprises a turbidity sensor for use in detecting a degree of soiling of liquid in the storage tank, wherein the control unit operates the fresh water supply device and thereby supplies fresh water to the storage tank when the degree of soiling of liquid in the storage tank is equal to or greater than a predetermined degree of soiling limit. 
     
     
       10. The conveyor dishwasher according to  claim 1 , wherein a bottom part of the zone in which final rinse liquid is sprayed has a storage tank opening which is connected by flow to the storage tank. 
     
     
       11. A conveyor dishwasher for cleaning wares, comprising:
 a conveyor device for conveying wares in a direction of conveyance through multiple zones of the conveyor dishwasher, including a front wash zone, a rear wash zone, a post-wash zone and a final rinse zone, 
 the rear wash zone having spray nozzles, a tank and a pumping device for recirculating wash liquid from the tank to the spray nozzles and spraying wash liquid through the spray nozzles onto wares, 
 the final rinse zone including spray nozzles for spraying final rinse liquid onto wares, 
 the post-wash zone having spray nozzles, a tank and a pumping device for recirculating liquid to the spray nozzles and spraying liquid onto wares, the tank of the post-wash zone arranged to receive final rinse liquid sprayed in the final rinse zone; 
 a storage tank, separate from the tank of the post-wash zone, for gathering some sprayed final rinse liquid; 
 a liquid transfer device, including a liquid line running from the storage tank to the rear wash zone and a pump, for controlling whether liquid is transferred from the storage tank to the rear wash zone; 
 at least one sensor device for determining liquid demand in the rear wash zone; and 
 a control unit configured for automatic operation of the liquid transfer device depending on liquid demand in the rear wash zone as indicated by the sensor device; 
 wherein walls are provided along a bottom part of the conveyor dishwasher where sprayed final rinse liquid collects, the walls positioned above an opening of the tank of the post-wash zone to permit a liquid level above the opening of the tank of the post-wash zone; and 
 a storage tank opening located in the bottom part and spaced from the tank of the post-wash zone, the storage tank opening connected by flow to the storage tank. 
 
     
     
       12. The conveyor dishwasher according to  claim 11 , wherein the at least one sensor device includes a turbidity sensor for detecting a degree of soiling of liquid in the tank of the rear wash zone, wherein the control unit operates the liquid transfer device when the detected degree of soiling in the tank of the rear wash zone is equal to or greater than a predetermined degree of soiling. 
     
     
       13. The conveyor dishwasher according to  claim 12 , wherein the at least one sensor device includes a liquid level sensor for detecting a level of the liquid in the tank of the rear wash zone, wherein the control unit operates the liquid transfer device when the detected liquid level in the tank of the rear wash zone is at or below a predetermined lower level. 
     
     
       14. The conveyor dishwasher according to  claim 11  further comprising a fresh water supply device that supplies fresh water to the storage tank, at least one sensor device provided for determining fresh water demand in the storage tank, wherein the control unit controls the fresh water supply device as a function of fresh water demand in the storage tank to supply fresh water to the storage tank when there is a demand for fresh water. 
     
     
       15. A conveyor dishwasher for cleaning wares, comprising:
 a conveyor device for conveying wares in a direction of conveyance through multiple zones of the conveyor dishwasher, including a wash zone, a post-wash zone and a final rinse zone, 
 the wash zone having spray nozzles, a tank and a pumping device for recirculating wash liquid from the tank to the spray nozzles and spraying wash liquid through the spray nozzles onto wares, 
 the final rinse zone including spray nozzles for spraying final rinse liquid onto wares, 
 the post-wash zone having spray nozzles, a tank and a pumping device for recirculating liquid from the post-wash zone tank to the spray nozzles and spraying liquid onto wares, the tank of the post-wash zone arranged to receive final rinse liquid sprayed in the final rinse zone; 
 a storage tank, separate from the tank of the post-wash zone, for gathering some sprayed final rinse liquid; 
 a liquid transfer device, including a pump and a liquid line running from the storage tank to the wash zone and having an outlet to deliver liquid to the tank of the wash zone, for controlling whether liquid is transferred from the storage tank to the rear wash zone; 
 at least one sensor device for determining liquid demand in the rear wash zone; and 
 a control unit configured for automatic operation of the liquid transfer device depending on liquid demand in the rear wash zone as indicated by the sensor device; 
 wherein the storage tank has an overflow over which liquid flows from the storage tank when liquid level in the storage tank exceeds a certain outflow level and the overflow is a path separate from a path defined by the liquid transfer device.